15 Tech Myths: Busted and Confirmed

Myth 7: You have to partition a large hard drive and/or defrag it often to get the best performance.

This is one of those myths that can start a bar fight at geekier watering holes. According to Mario Apicella, technology analyst and storage guru for PC World sister site Infoworld.com, defragging a large hard disk will boost performance on a Windows machine. Exactly how much of a boost depends on the number of files you change or delete each day.

"The OS has a silly habit of trying to reuse every free cluster, even if it's in the middle of a large occupied area and there's a lot of free space at the end of the volume," says Apicella. "So new files end up being scattered all over the drive, which means having to do several seek operations to bring them all together."

But in PC World tests, we found no noticeable performance lift after using a host of defraggers. Diskeeper Corporation, which makes a defragging utility, claims the practice can improve performance, but only if you have at least 20 percent free hard disk space. In short: Your mileage may vary.

Partitioning your hard disk into two or more logical drives won't necessarily speed up your system either, but it has a host of other benefits. For instance, it allows you to create a dual-boot system or separate files that don't change much (like your OS and apps) from those that do (your data and Internet cache). That will reduce fragmentation problems and make it easier to back up your system and/or replace the OS without endangering your data. (Check out our step-by-step instructions on partitioning your drive.)

Myth 8: Using high-speed flash cards in your digital camera lets you take photos faster.

High-speed memory cards allow a digital camera to save files faster, but that doesn't necessarily mean you can snap photos more quickly. "When you take a picture, the camera has to capture and process the image, then save it to the card," says Mike Wong, PR manager for memory-card maker SanDisk. "A faster card will only improve the latter part of the process--the save-file-to-card part."

If you use a speedy camera with slower memory, you may notice a lag on the memory side. But using a fast memory card with a slow camera is like putting race car tires on a Yugo--you'll mostly end up spinning your wheels, says Wong. "[The difference] can be significant in digital SLRs but less noticeable in many of the point-and-shoot types."

However, Wong says faster cards can reduce the amount of time it takes to upload photos to your computer, provided you also have a fast card reader. This may become more important as megapixels increase and card capacities grow.

Myth 9: Rechargeable batteries are more cost effective than disposable ones.

This one's not a myth, at least in most cases, but the cost effectiveness of rechargeable batteries depends upon the type of battery you choose and how often you use your gadgets.

Rechargeable nickel cadmium and nickel metal hydride batteries lose their charge quickly when stored, says Chris Calwell, VP of policy and research at Ecos Consulting, which publishes reports on the energy efficiency of consumer products. These batteries are a bad call for devices you use infrequently--such as a flashlight for emergencies. Rechargeable lithium ion batteries keep their charge much longer, but may not be available in the size you need. If lithium ion batteries are not available for your device and you don't use it frequently, it may save you money in the long run to go with disposables.

Duracell spokesperson Blayne Murphy agrees that usage is a key factor: "For heavy users of high-drain devices, such as digital cameras, rechargeables are definitely the most cost-effective solution. But if you are an occasional user who doesn't take a lot of pictures, rechargeables are not going to be convenient because they may not be ready when you need them."

Not only do rechargeable batteries cost more than disposables, but you also have to factor in the price of the charger, the electricity it consumes, and how many recharges the batteries can take before you have to replace them. "Our general advice," says Calwell, "is to buy lithium ion-based rechargeable products or nickel metal hydride products with as high of a rated capacity and as small of a charger as possible."